1. Technical Field
The technique disclosed herein relates to an image display device for adjusting parallax included in a three-dimensional (abbreviated to “3D” hereafter) image displayed using a projector, a television set, or a similar device.
2. Background Information
In recent years, a variety of 3D formats such as frame packing, side-by-side, top-and-bottom, and line alternative have been defined in relation to High-Definition Multimedia Interface (HDMI) Version 1.4a. There has also been an increase in popularity of a display method in which active shutter glasses are driven in a synchronized manner while a right-eye image and a left-eye image (together referred to as “LR images” hereafter) are alternately displayed at a high speed using the frame sequential method, whereby stereoscopic vision is obtained
For such displaying of LR images, a television or a projector that can be driven using the frame sequential method is often used. In particular, with regards to a projector, a larger screen size often results in a larger amount of parallax being included in an input image signal for the content, making it possible to provide an image with a greater stereoscopic effect.
However, the visual distance is more likely to decrease with increasing screen size, and the user may therefore experience motion sickness or biological discomfort due to parallax between the left and right eyes. For content for which image-capturing was performed without taking parallax angle into consideration, the amount of parallax contained in the input image signal can be excessive. In such an instance, again, the user experiences motion sickness or discomfort.
There has been proposed a method for controlling the display position of each of the LR images in the horizontal direction based on the amount of parallax between corresponding regions in the LR images, with an aim to achieve optimum stereoscopic vision (see Japanese Laid-Open Patent Application H8-9421).
A stereoscopic image device according to Japanese Laid-Open Patent Application H8-9421 has a left video camera for capturing a left-eye image, a right video camera for capturing a right-eye image and a stereoscopic display device. The stereoscopic display device controls the display position of each of the LR images in the horizontal direction based on control information that has been multiplexed with the LR images, the control information including focus information, zoom information, convergence angle, the amount of parallax for each segmented region, and the spacing between two video cameras.